Automatically engaging and disengaging gear box assembly

Abstract

A gear box assembly for automatically engaging and disengaging an output gear which is non-rotatably concentrically mounted on a driven axle shaft attached to plural wheels in a children's ride-on toy is described. The assembly includes an electric motor with a pinion driving plural driven gears, and a yoke which is pivotable between two positions and provides a mount for at least one of the plural driven gears. In one position, the yoke pivotally engages the output gear and drives the vehicle's wheels, and in another position, the yoke pivotally disengages the output gear thereby allowing the vehicle's wheels to freely rotate without driving or back-driving the motor or other gears. In the preferred embodiment, the yoke is counterbalanced for rotation about a defined axis. In alternative embodiments, the yoke includes a friction member for developing friction between one of the driven gears to rotate the yoke into engagement.

We claim: 
     
       1. In a vehicle which includes a driven axle shaft extending transversely of the vehicle having wheels secured thereto and an output gear concentric with the axle shaft non-rotatably connected thereto: a first gear mounted on the vehicle rotatable about a rotation axis;   an electric motor with an output shaft mounted adjacent the first gear with the output shaft paralleling the rotation axis and having a pinion mounted thereon, with the pinion in driving contact with the first gear;   a second gear in driving contact with the first gear; and   a yoke pivotally mounted about the rotation axis of the first gear and providing a mount for the second gear, wherein the yoke pivots to one position wherein the second gear engages the output gear and drives the vehicle's wheels when the motor is energized, and the yoke pivots to another position wherein the second gear disengages the output gear and allows the vehicle's wheels to rotate freely when the motor is de-energized.   
     
     
       2. The vehicle of claim 1 further including a gear housing mounted on the vehicle and at least one driven gear connecting the second gear and the output gear, wherein the housing encloses the first and the second gears, the motor, the at least one driven gear and the yoke and wherein the yoke is pivotally mounted on the housing. 
     
     
       3. The vehicle of claim 2, wherein the housing includes a motor boss joined therein for receiving the motor. 
     
     
       4. The vehicle of claim 2 wherein the yoke includes a friction member integral therewith, wherein the friction member engages at least one of the first or the second gears for developing friction therewith to rotate the yoke into engagement with the output gear when the motor is energized. 
     
     
       5. The vehicle of claim 2, wherein the yoke is counterbalanced about the first gear's rotation axis. 
     
     
       6. In a vehicle which includes a vehicle frame and a driven axle shaft having vehicle wheels secured to the ends thereof, a housing and gear box assembly unit secured to the vehicle's frame and providing a mounting for the axle shaft, the unit comprising: an output gear concentric with the axle shaft and non-rotatably connected thereto;   a first gear mounted on the housing;   a motor for driving the first gear;   a second gear in driving contact with the first gear;   a yoke providing a mount for the second gear wherein the first gear is rotatable about a rotation axis, and wherein the yoke is pivotable about the rotation axis, the yoke pivoting to one position in which the second gear engages the output gear to drive the vehicle's wheels when the motor is energized, and the yoke pivoting to another position wherein the second gear disengages the output gear when the motor is de-energized;   at least one gear selectively connecting the second gear and the output gear; and   a housing enclosing the output gear, first gear, second gear, yoke and the at least one gear.   
     
     
       7. The vehicle of claim 6, wherein the housing includes a motor boss for receiving the motor. 
     
     
       8. The vehicle of claim 7, wherein the yoke includes a fiction member integral therewith for engaging at least one of the first or the second gears to develop friction therebetween to rotate the second gear into engagement with the output gear when the motor is energized. 
     
     
       9. The vehicle of claim 7, wherein the yoke is counterbalanced about the first gear's rotation axis. 
     
     
       10. The vehicle of claim 7, wherein the yoke includes a friction member for engaging at least one of the first or the second gears to develop friction therebetween to rotate the second gear into engagement with the output gear when the motor is energized. 
     
     
       11. In a toy vehicle including a vehicle frame and a driven axle shaft having vehicle wheels secured to the ends thereof: a first gear having a concentric pinion mounted on the frame for rotation about a first rotation axis;   an electric motor with an output shaft mounted on the frame with the output shaft paralleling the first rotation axis and having a pinion mounted thereon in driving contact with the first gear;   a second gear having a concentric pinion mounted on the yoke for rotation about a second rotation axis, wherein the second gear is in driving contact with the concentric pinion gear on the first gear;   a third gear having a concentric pinion mounted on the frame for rotation about a third rotation axis wherein the third gear is in selective driving contact with the concentric pinion on the second gear;   an output gear concentric with the axle shaft and non-rotatably connected thereto, the output gear in driving contact with the concentric pinion on the third gear; and   a yoke, mounted on the frame and pivotable about the first rotation axis and providing a mount for the second gear, wherein the yoke automatically pivots to one position wherein the second gear engages the output gear when the motor is energized and the yoke automatically pivots to another position wherein the second gear disengages the output gear when the motor is de-energized.   
     
     
       12. The vehicle of claim 11, wherein the yoke includes a friction member joined thereon engaging the second gear for developing friction therebetween to rotate the yoke into engagement with the output gear when the motor is energized. 
     
     
       13. The vehicle of claim 11, wherein the yoke is generally counterbalanced about the first gear's rotation axis. 
     
     
       14. The vehicle of claim 12, wherein the friction member is in contact with the concentric pinion gear on the second gear. 
     
     
       15. The vehicle of claim 11, further comprising a housing mounted on the frame and receiving the axle shaft, enclosing the first, second, third, and output gears, the motor, and the yoke. 
     
     
       16. The vehicle of claim 15, wherein the housing further includes a motor boss for receiving the motor.